Grease gun



Malrch` 5, 1929. E. A. DE FOREST GREASE GUN `Filed Aug. 21, 1925 5Sheets-Sheet mmm!! Edgar Deres by Mm? In Veni-or.'

` March 5, 1929. E. A. DE FOREST GREASE GUN Filed Aug. 2l, 1925 5Sheets-Sheet March 5, 1929. E', A DE FOREST 1,704,179

GREASE GUN Filed Aug. 21, 1925 3 sheets-sheet 5 h .A m ,wm wf m A i mw.l l l v m ,f Q L i N r ./w M s E. m w .l l m l /,Z./ A 6 l/l/ I l l, NNm Aww 6% 0| v w n ,www

u a m m Patented Mar. 5, 1929.

UNITED STATES PATENT OFFICE.-

"EDGAR A. DEFOREST," F MINNEAPOLIS, MINNESOTA, ASSIGNOR TO GRAY COMPANY,

.,INC.,v OF MINNEAPOLIS,-MINNESOTA, A CORPORATION 0F SOUTH DAKOTA.

GREASE GUN.

Application led August 21, 1925. Serial No. 51,589;

My invention relates to grease guns. An ob] ect is to provide a deviceof this character by means of which grease for lubricating purposes maybe "cii'ectively delivered. W'hile intended more particularly for use inlubricating parts of motor vehicles, it will be obvious that there aremany other places where my device may be used to advantage for obtainingetlicient and timely lubrication of moving parts.

Thefull objects and-advantages of my invention will appear in connectionwith the detailed description thereof, and the novel features embodiedin my inventive idea will be particularly pointed out i'n the claims.

` 'In the accompanying drawings which illustrate some of the forms inwhich my in-y vention may be embodied, Fig. l is a view of one form ofthe device in vertical section. Fig. 2 is a View of another formlof thedevice in vertical' section. Fig. 3 is a view in horizontal section onthe line 8-8 of Fig. 1. Fig. 4is a view of still another form of thedevice in vertical section. Fig. 5 shows a wiring diagram with a circuitclosing device shown in section.

Referring first to the construction shown in Figs. 1 and 3. The numeral10 designates a grease receptacle which is provided with a detachablecover 12 held in place by screw devices 14. The cover 12 at its centeris provided with anupward tubular extension 16, the upper end of whichhas a thickened portion 18 which slidably receives a screw threaded rod20 having a hand wheel 22 secured at its upper end. Secured to the lowerend of the rod 20 is a stem 24 which extends downwardly and whose lowerend carries a disk 26 which rests upon a stem 28 carried by the uppersurface of a plunger 3() around the periphery of which is a packing 32eX- panding against the inner surface of the receptacle 10.' The lowerend of a sleeve 84 fits over the stem 28 and is secured thereto by apin36 while the upper end of the sleeve has a shouldered portion 88 whichrotatably engages the stem 24. Ther disk 26 is rotatably mounted withinthe sleeve 34. A ball-bearing 40 is interposed between the disk 26andthe shouldered member 88. The threads of the rod 2O engage internalthreads of a sleeve 42 having a cupped upper end 44. A. coiled spring 46surrounds the rod-20 between the sleeve 42 and the cover 12, the lowerend of vthis spring being secured in any suitable manner in the cuppedportion 44 of the sleeve 42, and the upper end of the spring.,

12 carrying the plunger 3'() may be removed from the receptacle 10,which is then nearly filled with grease. Before replacing the plunger,the hand wheel 22 is turned to feed the plunger up to the sleeve 42, therod 2O sliding loosely up thru the member 18. When the plunger isreplaced in the container, it will be forced resiliently against the`grease by the spring 46 and as the grease is used the hand Vwheel 22 isfrom time to time turned to move the plunger downwardly which actionoccurs on account of the threaded engagement of the rod 20 with thesleeve 42. The grease is thereby constantly subjected to the resilientdownward thrust of the plunger, due to the expansion l ing 48 whoseouter' surface 50 engages the receptacle and has an outturned iiange 52at its lower end engaging an outturned ange 54 onthe lower end of thereceptacle. Screws 56 pass thru these iianges and thru the margin of abottom plate 58 of brass. The casting 48 contains an annular chamber inwhich a wire coil 60 is placed, this coil being includedin an electriccircuit formed by wire 62 attached to any convenient circuit closingdevice. A conventional form of such device is shown in Fig. 5 in whichthe wires are attached to binding posts 64 and 66 insulatively mountedon a casing 68 containing a plunger 70 normally held by a spring 72, outof Contact with the binding posts. l/Vhen the plunger is depressed theposts 64 and 66 are bridged and the circuit is completed for energizingthc coil 60. This coil is heldin its chamber by a screw ring 74, whilean armature plate 76 of iron is slidably mounted within the portion 5()of the casting 48. This casting has a central de-k pression, the. lowerwall of which has an open center formed by an upward-extension which isexternally screw threaded and engaged by screw threads on the lowerportion of a tubular member 80. A coiled spring 82 interposed betweenthe member 80 and the armature plate 76 keeps the latter retracted whenthe coil 60 is not energized. The opening in the upper end of thetubular member 80 is provided with a downwardly opening check valve 84which permits entrance of grease into the upper port-ion of the tubularmember 80 from which a tube 86 leads out thru the wall of the container.The tube 86 at its outer end has a union 88 containing an outwardlyopening check valve 90. 'lhe union is connected to a pipe 92 whiehdelivers the grease to the place where it is to be utilized. Secured tothe armature plate 76 is a piston 94 which operates in the tubularmember 80 which serves as a cylinder. Vhen the circuit closing device isactuated to energize the coil 60, the armature plate 76 is movedupwardly and carries the piston 94 with it, the upper end of the lattermoving from the dotted line position indicated at 96 toward the upperend of the member 80 and forcing the grease in said member out thru thetube 86 and the pipe 92. When the circuit closing device is released,the armature plate 76 carries the piston downwardly thereby producing avacuum in the upper portion of the cylinder 80 which causes grease tobe-sucked in past the check valve 84. In the form of invention shown inFig. 2 the casting 48 and the parts associated directly therewith' areutilized without the container and the mechanism in the upper portionthereof which is shown in Fig. 1 whereby the expense of construction ismuch reduced. The same reference characters are used in Fig. 2 so far asthey are applicable. In-this form of the invention, the upper end of thetubular member 80 is externally screw threaded to receive the .threadsof a coupling member 98, the interior of which is connected by a pipe100 with a suitable grease receptacle. This form of invention isintended particularly for use in individual garages while that shown inFig. 1 is intended for use at greasing stations. The form of inventionshown in Fig. 4 is intended to be mounted in any rconvenient place.directly upon a motor vehicle. `This form includes a hollow ironcasting 102 provided with a brass screw cap 104. The lower wall 106 ofthe casting conn tains a screw threaded depression in which is screwedthe lower end of a tubular brass member 108, whose upper end has anoutwardly extending annular flange 110, whereby a chamber is formedwhich in the form here shown contains fourcoils v112, 114, 116 and 118.These coils as shown at right hand side have a common lead 120 and atthe left hand side have separate leads122, 123, 124 and 125 for apurpose which will be referred to later. The tubular member 108 slidablyreceives a solenoid core 126 attached to a plate 128 slidable in theupper portion of the casting 102. The central portion of the wall 106 isformed with a hollow downward extension 130 in which works a rod likepiston 132 extending downwardly from the lower end of the solenoid core126. The bore in the extension 130 is enlarged at its upper portion toprovide a shoulder 134 between which, and the lower end of the core-]26, a coiled spring 136 is interposed to hold the core upwardly whenthe coils are not energized. The extension 130 is provided with a hollowlateral extension 138 which is internally threaded to receive a hollowexternally threaded projection 140cxtending out from a grease container142 provided with a screw cap 144, which permits it to be refilled. Thelower end of the extension 130 is externally threaded to receive acoupling n'iember 146, containing an outwardly opening check valve 148.Attached to the lower end of the coupling 146 is a pipe 150 whichdelivers the grease to the place where it is to be utilized. vWhen thespring 136 moves the core 126 upwardly the lower end of the piston 132slides past the opening in the extension 138 and the vacuum which isproduced in the lower portion of the extension causes grease fromv thecontainer 142 to be drawn in. When the coils are energized the piston132 descends and forces grease out thru the pipe 150. The four coilsincluded in the hollow iron casing 102 are spirally wound in the samedirection with a common lead 120 on the right hand side as shown, andindividual leads 122, 123, 124, and 125 on the left hand sides of thecoils` 112, 114, 116 and 118, so that several combinations can beobtained in order to lit the electrical conditions of the place wherethe device is to be utilized. For instance, when the coils are connectedserially with the proper amount of resistance to suit the standardconditions of voltage and amperage, the maximum voltage with the minimumainperage is obtained, while when the coils are connected in groups oftwo or more the opposite eflect is obtained, viz, the maximum amperagewith the minimum voltage. The first case is that of the usual lightingcircuit and the second is that of the storage battery. Othercombinations with outside rheostat control enable the pressure to beconstrained under remote control for automatic lubrication of greasecups or oil cups located at any distance from the source of control asin the case of line shafting, power stations or other devices andapparatus in which automatic lubrication is of great advantage.

I claim: l

1. A grease gun comprising a source of supply of grease, a tubularmember connected with said source, a delivery pipe connected to saidtubular member, a iston working axially in said tubular mem r, amagnetically attracted device to which the outer end of said piston issecured, an iron member dis )osed concentrically with rela.- tion to saitubular member. a wire coil surrounding said iron member, acircuitclosing device for said Vcoil located at a distance remotetherefrom whereb said piston may be moved inwardly or eject-ing greasethrough said delivery pipe, and a spring for returning said piston whensaid circuit-closing device is open.

2. A grease gun comprisin a tubular member, a suppl pipe and a eliverypipe connected with t e interior of said tubular member at one endthereof, a piston working through the other end of said tubular member,an electrically o erated device for caus- -mg movement of sai piston inone direction,

a. circuit for said electrical device, means for opening and closingsaidcircuit, and a EDGAR A. DE FOREST.

